It definitely is with a bit of DETERMINATION.An Undertale port would actually be possible.
I started with porting the Game Maker: Studio engine to 3DS, as that's what Undertale was based off of, then I said a bad pun, put Undertale's data.win in there, drew rule 34 of Toriel playing 3DS, and then viola, I got Undertale 2: Electric Boogaloo, on 3DS.